Horn-nosed boxfish (Ostracion rhinorhynchos)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Chordata · Class: Teleostei · Order: Tetraodontiformes · Family: Ostraciidae · Genus: Ostracion.

Accepted name: Ostracion rhinorhynchos · Authority: Bleeker, 1851 · Taxonomic status: accepted · AphiaID: 278935.

Synonyms and superseded combinations recorded for this taxon: Ostracion rhinorhynchus Bleeker, 1851; Ostracion rhynorhyncus Bleeker, 1851; Rhynchostracion rhinorhynchos (Bleeker, 1851); Rhynchostracion rhinorhynchus (Bleeker, 1851); Rhynchostracion rhynorhynchus Bleeker, 1851.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=278935 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

Measured values published by FishBase for Ostracion rhinorhynchos. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 35 cm · Depth range: 35–50 m · Habitat zone: reef-associated · Body shape: short and / or deep · Vulnerability index: 25 of 100 · Fishery importance: of no interest · Aquarium trade: potential.

FishBase notes: Inhabits rubble substrates in channels between sheltered inner reefs or in deep sandy lagoons around coral patches (Ref. 48637). Solitary or in pairs (Ref. 90102). Generally uncommon species (Ref. 9710) that inhabits coral reefs and flat bottoms in coastal areas. Feeds on benthic invertebrates.

Source: FishBase species summary (SpecCode 8288) — https://www.fishbase.se/summary/Ostracion-rhinorhynchos.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

401 georeferenced occurrence records for Ostracion rhinorhynchos are published through GBIF from 15 countries or marine areas. The map above plots 92 distinct locations from a sample of 401 records, omitting 29 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: Australia (124); Philippines (82); Hong Kong (58); Indonesia (49); Thailand (21); Chinese Taipei (16); Malaysia (14); Viet Nam (13); China (8); Sri Lanka (6); India (5); Japan (2); Cambodia (1); Myanmar (1); Singapore (1).

Source: GBIF Occurrence Search (taxonKey 5213779) — https://www.gbif.org/occurrence/search?taxon_key=5213779&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=278935 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Conservation status (IUCN Red List)

The IUCN Red List assesses Ostracion rhinorhynchos Bleeker, 1852 as Least Concern (code LC). No trend, population estimate or threat analysis is given here, because none is available from this source without the Red List API; follow the source link for the full assessment, including its date.

Source: IUCN Red List of Threatened Species (taxon 193727) — https://www.iucnredlist.org/species/193727/0; GBIF IUCN Red List category endpoint (taxonKey 5213779) — https://api.gbif.org/v1/species/5213779/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

Ostracion rhinorhynchos was first formally described in 1851 by the Dutch physician, herpetologist and ichthyologist Pieter Bleeker with its type locality given as Jakarta on Java. This species is classified in the genus Ostracion which the 5th edition of Fishes of the World classifies within the family Ostraciidae in the suborder Ostracioidea within the order Tetraodontiformes.

Ostracion rhinorhynchos is classified in the genus Ostracion, this name means "little box" and is an allusion to the shape of the body of its type species, O. cubicum. The specific name, rhinorhynchos is a compound of rhinos, meaning "beak" or "bill", with rhynchos, which means "snout", an allusion to the to cone-shaped protuberance on the snout of adults.

Ostracion rhinorhynchos has 9 soft rays supporting both the dorsal and anal fins while the caudal fin has 10 rays, 8 of which are branched. Males have a large, blunt, conical protuberance above the mouth and in front of the eyes. The oblong carapace has a poorly developed ridge on the back with sharp ridges on the lower flank, although there are no spines. The upper body is pale grey and may be spotted, spotting is more prominent on the caudal peduncle and less clear on the flanks. The lower body is white and the fins are dusky. The horn-nosed boxfish has a maximum published total length of 35 cm.

Ostracion rhinorhynchos has a wide distribution in the Indian and Pacific Oceans. It occurs from the Maldives and Sri Lanka east to Chuuk State in Micronesia, north as far as southern Japan. It is found at depths between 1 and 50 m on substrates of rubble, as well as flat areas and on reefs.

Source: Wikipedia: Ostracion rhinorhynchos — https://en.wikipedia.org/wiki/Ostracion_rhinorhynchos (CC BY-SA 4.0). Accessed 2026-09-23.